Basically, you have to get the cultivation "Transcendent" (level 59) or higher to activate the quest..
To start this off, here are the steps:
1. Clear FB 59 (kill all 5 bosses) for cultivation "Transcendent"
2. Mine the statue in the middle of FB
3. Leave party (leave FB) and go to Celestial guy in Heaven's Tear to complete cultivation.. Have someone else in your party to hold the cave so mobs don't respawn
4. Talk to Celestial and get the cultivation "Transcendent"
5. Pop-up appears (in aqua color) from First Mage (the NPC in Tellus)
6. Go to Tellus as quickly as possible.. Easy way is to just tele from Silver Pool --> Archosaur --> Tellus City
7. Talk to First Mage and pick quest from him.. After picking quest, DO NOT DIE until you finish the quest or it'll reset the quest all over..
8. Go to Restless Remnants to mine Red Lotus... BEWARE this one has hidden timer, don't wait for too long or you can't mine the item.. Best way is to just fly there since it's close from Tellus..
9. Use town portal to Tellus
10. Tell your party to invite you back to party..
11. Tele to Archosaur --> Valley of Disaster
12. Go to the middle of the cave, find the Calm of Fire statue near fire entrance (between Earth and Fire entrance)..
13. Mine the statue to spawn Cragglord..
14. Cragglord has 150k hp (non-elemental).. Do both range and melee attack.. Melee attack hits 800 damage (on 9xx physical defense).. Magic hits around 150 damage (on 3k magical defense)..
15. Kill Cragglord under 5 minutes.. DO NOT DIE until quest is finished..
16. Talk to Cragglord npc after you kill him to receive Cragglord skillbook..
This is what I do.. I've read a lot of people complaining about failing Cragglord quest.. Follow the above steps exactly and you won't fail.. Have a cleric comes to heal since Cragg can easily 2 shotted you (the mystic) and 3 shotted level 10 skill (level 59 Devil Chihyu)..
Tips when fighting Craggy:
1. Cragg runs alot and not staying at one place.. Debuff plants don't work well, unless you lyse the plant instantly (imo, cost too much mp at level 59).. Make sure lysing is level 10 to get the debuff effect.. Otherwise, don't try..
2. Healing plants is a good alternative (Vital Herb/Healing Herb) instead..
3. Always cast falling petals on yourself.. (recommended level 10 falling petals)..
4. Transfer mana to Chihyu.. Use the skull slap skill to stun rhape Cragg..
5. Using Salvation can be a good alternative.. However at level 59, the max you can get on Savy is level 5.. I don't know if it works better than using Chihyu.. Using Savy means you force yourself on soloing Craggy without the added damage/stun damage from Chihyu.. But it's safer to take damage when using Savy..
6. Using Storm Mistress is heavy mp and at level 59, you don't have access to level 75 mp pots (herb yuanxiao).. Unless you are mp charmed, don't even bother using Mistress..
7. Drop Thicket whenever you have 2 sparks for the silence/freeze chance and the damage..
Note: Buy Thicket in Silver Pool Mystic Trainer directly after you get "Transcendent"..